Collapsible containers for the administration of medical solutions are well known and are disclosed, by way of example, in U.S. Pat. Nos. 3,519,158, 4,140,162, 4,170,994, 4,136,694, 3,986,507, 3,304,977, 3,788,374, 3,364,930, 4,191,231, and 4,049,033. Typically, such a container when used for the storage and administration of parenteral fluids, has an inlet port as well as an outlet port. The outlet port is intended to be coupled to an administration set and is therefore commonly referred to as the administration or set port, whereas the inlet port is designed to permit the injection of therapeutic agents and nutrients into the partially prefilled container and is sometimes identified as the med port. Such a container may contain a partial filling of a sterile solution such as saline or dextrose to function as a diluent for the injected additive. The diluted drug or nutrient is then administered to a patient by means of the administration set which may be either directly or indirectly (i.e., through another parenteral solution set) coupled to the patient.
Maintaining the sterility of the fluid to be administered is clearly of major importance. It has been found, however, that careless or inattentive handling of a parenteral solution container, as the connections are being made for fluid administration or additive introduction through the respective outlet and inlet ports, may create significant risks of contamination. Such risks may be increased where emergency situations are presented that require quick manipulation of the various components, or where extended storage conditions causes components to stick together or to separate in a manner differently than intended. For example, a conventional administration port is often sealed by a soft rubber sealing disc held in place by a thin metal tear-off cap. Should the disc remain in place upon the neck of the container after the cap is removed, a user attempting to remove the disc might inadvertently touch and contaminate the sterile end surface of the neck, and such contamination may then be transferred to the contents of the container when the spike of the administration set is later plugged into the outlet port.
It is therefore an object to provide a container for medical solutions having improved inlet and outlet port constructions to reduce possibilities of contamination during storage and use, improve the ease of handling such a container when fluids are to be withdrawn or introduced and, at the same time, increase the ease and efficiency by which such a container may be manufactured. Since such containers are discarded following use, greater efficiencies in production resulting from improvements in construction tend to benefit patients in terms of both greater safety and lower cost.
In brief, the medical solution container of this invention may take the form of a collapsible bag having inlet and outlet ports. Each port has a tubular neck enclosed at its end by a metal cap. In the case of the outlet or administration port, a sealing disc or liner of soft elastomeric material is interposed between the end surface of the neck and the tear-off metal cap. The disc has planar surfaces and is provided with an integral circumferentially-extending rib projecting outwardly from its side surface. Ideally, the rib is spaced equal distances from the planar faces and has a diameter (in an undeformed state) greater than the inside diameter of the cap. Specifically, the rib should have a radial dimension less than half distance between each of the planar faces of the disc, and should have an axial dimension within the range of about 15 to 30% of the thickness of the disc. When the parts are assembled, the rib engages the inside surface of the cap and may be deformed thereby without, at the same time, causing any significant deformation of the disc's planar surface in sealing engagement with the end surface of the neck. Because of the frictional engagement between the disc and cap, the disc tends to be removed as the cap is torn away from the neck; however, should the disc happen to remain upon the neck after the cap is removed, the outwardly-projecting rib may be easily gripped or engaged by the fingers, and the disc may be lifted from the neck, without contacting and contaminating the sterile end surface of the neck.
The neck of the outlet port includes a tapered annular collar disposed within the neck and formed integrally therewith for slidably and sealingly engaging the hollow spike of an administration set. The opening defined by the collar (when the collar is unstretched) is smaller than the reduced portion of the bore adjacent thereto, thereby helping to assure effective contact between the collar and the inserted spike. The neck also includes an integral membrane adapted to be pierced by the spike, with the portion of the bore directly beneath (or proximal to) the membrane being of larger diameter to accommodate material of the membrane when such membrane is pierced, deformed, and displaced by the spike.
It has been found that a highly effective tapered annular collar may be formed in a simple molding operation if the distal wall portion of the neck is provided with an enlarged bore to accommodate outward flexing or stretching of the collar as the mold section is withdrawn, and if the inner and outer surfaces of the collar slope inwardly and distally (at an angle of about 5.degree. to 15.degree. measured internally) with the outer surface having a greater acute angle of slope (measured from a line extending in an axial direction). The differential between the angles of slope of the inner and outer surfaces should be within the range of 3.degree. to 10.degree. with a preferred differential being about 5.degree..
The tubular neck of the inlet or medication port has an internal annular shoulder facing the open distal end of the neck and is also provided with a plurality of longitudinal ribs projecting inwardly from the surface of the bore above (distal to) the shoulder. The ribs serve to guide the body of an elastomeric stopper into sealing engagement with the shoulder while themselves making only limited engagement so as to avoid possibilities of interference with the formation of an effective end seal between the stopper and shoulder. Since the seal occurs at the end of the stopper, contact between the fluid contents of the container and the elastomeric material of the stopper is more limited than in prior constructions, a factor that may be of some significance depending in part on the nature of the contents and the composition of the stopper.
Other important advantages, objects, and features of the invention will become apparent from the specification and drawings.